Contraction of the pupil during surgery creates substantial difficulty for the surgeon because it inhibits visability and access with respect to the eye during the surgical procedure. For certain procedures, the pupil needs to be enlarged beyond its normal size. Contraction of the pupil during the course of intraocular surgery often takes place. Also, going into surgery, the pupil frequently will not dilate adequately using pharmacologic agents so that surgical maneuvers can be effectively and safely performed. Resistance to dilatation may be due to structural changes in the iris induced by disease such as uveitis, long standing miotic therapy, senile sphincter atrophy, or diseases such as diabetes or pseudoexfoliation of the lens capsule. Various surgical techniques to mechanically enlarge the pupil are not uniformly effective, are time consuming, and often result in permanent defects in the iris sphincter.
Typical prior art devices to accommodate pupil dilation range from being essentially inoperative to being cumbersome, time consuming to insert, and essentially ineffective. Among these devices are those shown in U.S. Pat. Nos. 3,490,455; 4,037,589; 4,257,406; 4,387,706; and 4,782,820.
Therefore, a principal object of this invention is to provide a pupil expander that can be quickly and easily inserted into the eye.
A further object of this invention is to provide a pupil expander that can be quickly and easily removed from the eye at completion of surgery.
A still further object of this invention is to achieve a gradual incremental expansion of the pupil so as to prevent injury to the delicate iris structure during insertion. In addition, this controlled stretching of the pupil to a precisely determined and limited extent may restore the pupil to a more normal and desirable size, improving its function as an iris diaphram.
A still further object of this invention is to prevent the over-stretching of the pupil during the operative maneuvers by limiting its expansion to a precise, predetermined size just large enough to accomplish the intended surgical maneuvers.
A still further object of this invention is to attach the appliance securely to the iris by the clamping effect of its "C" cross section so that the entire pupil aperture created can be transposed in the plane of the iris by gentle lateral pressure on the ring thereby exposing additional fields for surgical maneuvers.
A still further object of this invention is to provide sustained dilation and protection of the pupil margin during prolonged surgical procedures such as training in phacoemulsification. The appliance would also allow re-expansion of the pupil where the pupil constricts during the course of a surgical procedure thereby restoring visibility and surgical access.
A still further object of this invention is to provide an expander which can be made in different sizes depending on the anticipated surgical procedure such as cataract surgery, retinal repair, vitreous surgery, etc.
A still further object of this invention is to provide a pupil expander that will stay in place once it is inserted, and which will not irritate or damage the eye tissues.
A still further object of this invention is to provide a pupil expander which can be easily shipped, stored and otherwise handled and manipulated.
A still further object of this invention is to provide a pupil expander which will provide the surgeon with good visibility of the eye and will not interfere with the surgical procedures.
A still further object of this invention is to provide a pupil expander which will provide a method of inserting the pupil expander of this invention in a quick and safe manner.
These and other objects will be apparent to those skilled in the art.